Fly Me to the Moon

1. Fly me to the Moon* On HW/SW used by Apollo missions to land on the Moon April 1st 2015, Martin.Dvorak@mindforger.com* a song originally written by Brad Howard in 1954 and recorded by Frank Sinatra in1964

2. Why? Aim for deep space / universe understanding? Aim for technological advance with huge impact on humanity? Seek a solution to a crucial problem enabling humans to alive? Another purely practical reason? …

3. Bring alien technology from the dark side of the Moon? Why?

4. Space Race as a part of Cold War propaganda

5. Space Race Timeline

6. Space Race Timeline: Computers Evolution Intel founded 1968

7. … 9x around the Moon & 6x on the Moon Apollo Program: Mission(s) & Timeline • Apollo 1 1966/02/22 - 1st flight of Saturn 1b • Apollo 2 1966/07/05 - fuel tank test • Apollo 3 1966/08/25 - sub-orbital Saturn 1b test • Apollo 1 1967/01/27 - pre launch cabin fire (Block I) • Apollo 4 1967/11/09 - 1st test of Saturn V booster • Apollo 5 1968/01/22 - test of Saturn V booster & LM • Apollo 6 1968/04/04 - test of Saturn V booster • Apollo 7 1968/11/11 - 1st manned Saturn 1b • Apollo 8 1968/12/21 - 1st manned Saturn V around Moon • Apollo 9 1969/03/03 - 1st manned LM • Apollo 10 1969/05/18 - 1st manned LM around Moon • Apollo 11 1969/07/16 - 1st manned landing on the Moon • Apollo 12 1969/12/14 • Apollo 13 1970/04/11 - SM explosion & LM as life boat • Apollo 14 1970/01/31 • Apollo 15 1971/07/26 - 1st lunar rower excursion • Apollo 16 1972/04/16 • Apollo 17 1972/12/07 - Final manned landing on M

8. 3 stages, 111m, service + lunar + command modules AGC Drill Down: Saturn 5

9. AGC Drill Down: Saturn 5 Žižkovská věž 213m

10. Apollo PGNCS • PGNCS == inertial guidance system • Navigation (speed, position, attitude): • Inertial: Inertial Measurement Unit - vector & gyroscope • Optical: Optical Unit - sextant (position & orientation) • Radio: Radar(s) - radio beacon & Doppler (v; 10mm/s) • AGC == PGNCS computer • Both on CM and LM • Developed by MIT, manufactured by GM The Primary Guidance, Navigation and Control System aka “pings” PGNCS w/ AGC @ Lunar Module

11. AGC: Apollo Guidance Computer • Digital computer = DSKY + Block I/II • Both on CM and LM • Guidance + navigation + control • NASA deep space net > vector > AGC • DSKY = numeric display & keypad • Numbers display: vectors e.g. space craft attitude & velocity delta • Commands: verb & noun two XX numbers w/ action & data • Units: metrics (internal) > US (DSKY) • 2xCM & 1xLM • Block I/Block II = digital computer • Developed by MIT in 1966 w/ Raytheon • fridges > WW2 > defense

12. AGC: Hardware • Lead: Charles Stark Draper • “father of inertial navigation” • RAM 3.8kB (Apollo 14 reprogramming) • ROM 74kB of LOL memory • “little old lady” - core rope memory • Registers: 4 central 15+1b + ~20 specific • Instructions: 11, 3b+12b (opcode + addr)* • Interrupts: 5, Bus: 16b RD + 16WR • Logical module (not CPU): • 4.100/2.800 (Block I/II) integrated circuits (1958) ICs > logic modules > Block I/II • Timing: 2.048 MHz referential + aux timers • ~32kg, ~70W/55W + stand-by, 61x32x17cm • Water cooling RAM ROM Logic module ICs

13. AGC: Software • Lead: Margaret Hamilton (31) @ MIT • Exec OS w/ 8 jobs • Cooperative multi-tasking • Interrupt driven priority* job waitlist • Margaret: • Coined term software engineering & set dev standards • Designed virtual machine ~ robust sophisticated interpreter • new (pseudo) instructions & lower memory consumption • buffer overflow & cycle stealing handling (RAM w/o CPU) • Her robust AGC design avoided Apollo 11 crash • … when landing on the Moon: 3’ > radar (activated by mistake) > overload (interrupts) > alarms > … but still running* + 2’’ from death Necessary software and programming techniques did NOT exist > to be designed Margaret Hamilton lead Apollo flight software engineer

14. AGC: Try it Yourself! • AGC emulators: • JavaScript • http://svtsim.com/moonjs/agc.html • Project Apollo NASSP emulator • http://sourceforge.net/projects/nassp/ • Original AGC source code: • https://code.google.com/p/virtualagc/ • Comments & thoughts & ideas: • news.ycombinator.com

15. Lessons Learned • Simple • Reliable • Robust • Efficient … design • Improvise • Handle failure gracefully • Work with users astronauts on UX • Unit tests prove your code • Trust in skilled crew, not in computers They would not let as fly the moon today…